TY - JOUR
T1 - Atomic Plasma Grafting: Precise Control of Functional Groups on Ti3C2Tx MXene for Room Temperature Gas Sensors
AU - Wang, YIng
AU - Fu, Jimin
AU - Xu, Jiangang
AU - Hu, Haibo
AU - Ho, Derek
N1 - Funding Information:
This work was financially supported by the Hong Kong University Grants Committee (CityU 11213222), Hong Kong Innovation and Technology Commission (ITS/166/19), and the City University of Hong Kong (6000776 and 9667245).
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/3/8
Y1 - 2023/3/8
N2 - Gas sensing properties of two-dimensional (2D) materials are derived from charge transfer between the analyte and surface functional groups. However, for sensing films consisting of 2D Ti
3C
2T
x MXene nanosheets, the precise control of surface functional groups for achieving optimal gas sensing performance and the associate mechanism are still far from well understood. Herein, we present a functional group engineering strategy based on plasma exposure for optimizing the gas sensing performance of Ti
3C
2T
x MXene. For performance assessment and sensing mechanism elucidation, we synthesize few-layered Ti
3C
2T
x MXene through liquid exfoliation and then graft functional groups via in situ plasma treatment. Functionalized Ti
3C
2T
x MXene with large amounts of −O functional groups shows NO
2 sensing properties that are unprecedented among MXene-based gas sensors. Density functional theory (DFT) calculations reveal that −O functional groups are associated with increased NO
2 adsorption energy, thereby enhancing charge transport. The −O functionalized Ti
3C
2T
x sensor shows a record-breaking response of 13.8% toward 10 ppm NO
2, good selectivity, and long-term stability at room temperature. The proposed technique is also capable of improving selectivity, a well-known challenge in chemoresistive gas sensing. This work paves the way to the possibility of using plasma grafting for precise functionalization of MXene surfaces toward practical realization of electronic devices.
AB - Gas sensing properties of two-dimensional (2D) materials are derived from charge transfer between the analyte and surface functional groups. However, for sensing films consisting of 2D Ti
3C
2T
x MXene nanosheets, the precise control of surface functional groups for achieving optimal gas sensing performance and the associate mechanism are still far from well understood. Herein, we present a functional group engineering strategy based on plasma exposure for optimizing the gas sensing performance of Ti
3C
2T
x MXene. For performance assessment and sensing mechanism elucidation, we synthesize few-layered Ti
3C
2T
x MXene through liquid exfoliation and then graft functional groups via in situ plasma treatment. Functionalized Ti
3C
2T
x MXene with large amounts of −O functional groups shows NO
2 sensing properties that are unprecedented among MXene-based gas sensors. Density functional theory (DFT) calculations reveal that −O functional groups are associated with increased NO
2 adsorption energy, thereby enhancing charge transport. The −O functionalized Ti
3C
2T
x sensor shows a record-breaking response of 13.8% toward 10 ppm NO
2, good selectivity, and long-term stability at room temperature. The proposed technique is also capable of improving selectivity, a well-known challenge in chemoresistive gas sensing. This work paves the way to the possibility of using plasma grafting for precise functionalization of MXene surfaces toward practical realization of electronic devices.
KW - 2D material
KW - MXene nanosheets
KW - PDOS
KW - plasma functional group grafting
KW - room temperature gas sensor
KW - surface functionalization
UR - http://www.scopus.com/inward/record.url?scp=85148871345&partnerID=8YFLogxK
U2 - 10.1021/acsami.2c22609
DO - 10.1021/acsami.2c22609
M3 - Journal article
SN - 1944-8244
VL - 15
SP - 12232
EP - 12239
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 9
ER -